Johnson Spitfire

I see every now and again a cartridge coming up for sale advertised as a 5.56x33 Johnson Spitfire or a 5.7mm MMJ.
I have heard these cartridges were trialled in the US by the military.
How does one differentiate between an original round and the host of copies and numerous similar wildcats? Are there particular headstamps or projectile types to look out for?
Cheers guys :)


Good luck!

The 30 carbine case necked to 22 goes back to 1945 when the little guns became available to civilian shooters. There are probably about 15 different versions in 22 caliber alone, and I-don’t-know-how-many in other calibers.

Col Johnson did indeed propose his cartridge and his Carbine conversion as a military weapon and the Army did some very preliminary testing before rejecting the idea. He also proposed it as a possible police combination with the same results. He then decided to offer it on a commercial basis and even produced boxed ammunition for it bearing his name.

How do you tell one cartridge from another? I don’t think you can. If anybody tries to sell you one and makes claims for it’s provenance, be leery unless they can back up their claims. Even boxed and labeled cartridges are suspect, in my own humble farm-boy opinion.

Then you have all of the different Carbines, both conversions and new made, and the wildcat cartridges that may differ in name only. I won’t even try to go there. (Somebody else will, I am sure)

Also, don’t confuse the cartridge with the other “22 CARBINE”, the experimental 22 SCHV, 22 Gustafson, 22 APG which is a legitimate collectable.

And that’s all I know about that.


I have had several of the Johnson boxes like Ray showed the picture of. All had round nose copper full metal jacketed bullets in resized .30 Carbine cases with military headstamps, early 1950s Lake City as I recall.